Cyclone Grant

A gale warning was issued for Darwin and the Tiwi Islands on 24 December.[6] The system intensified on 25 December, reaching Category 2 status in the afternoon,[7] and a cyclone watch was declared between Dundee Beach and Nhulunbuy, with a cyclone warning issued for areas between Cape Fourcroy and Milingimbi including the Tiwi Islands.[8] The system crossed Van Diemen Gulf and made a second landfall east of Point Stuart in the early morning of 26 December. Shortly thereafter the cyclone was downgraded to Category 1,[9] and by that afternoon it was downgraded to a tropical low as it passed Jabiru in Kakadu National Park.[10] Jabiru Airport had received 71.0 mm (2.80 in) of rain by 9:00am on 26 December.[11][12] On 27 December the system was moving slowly south-east across Arnhem Land,[13] causing heavy rainfall. Ediths Fall Ridge recorded 385.0 mm (15.16 in) of rainfall, which produced damaging flooding.[14] A cyclone watch was issued on 27 December from Nhulunbuy to Numbalwar, including Groote Eylandt.[15]

Flooding associated with the system in the Katherine area cut off the Stuart Highway, washed cars off bridges and derailed a train.[15] The Adelaide–Darwin railway was severely damaged by the derailment of the Genesee & Wyoming freight train. The Ghan was forced to stop with 200 passengers in Katherine.[16] One week after the cyclone had passed freight companies were poised to raise transportation costs as shipping to Darwin would need to be done by road.[17] The railway between Katherine and Darwin would be out of service until the end of January 2012.[18]

On 28 December the system moved eastward, bringing with it heavy rainfall to the Roper-McArthur River districts.[19]

A cyclone watch was issued for Queensland for coastal areas from Thursday Island to Gilbert River Mouth[19] but was later cancelled when the system did not re-intensify to Category 1 strength. Late on 29 December the system as a tropical monsoon low was northwest of Pormpuraaw on the Cape York Peninsula[20] before making landfall in the early morning of 30 December south of Wiepa[21] near the aboriginal community of Aurukun.[22] A severe weather warning was issued for the Peninsula, North Tropical Coast and Gulf Country districts.[23] Later on 30 December the monsoon low passed Coen and out into the waters of the Coral Sea.